Effect of ionic conductivity of zirconia electrolytes on the polarization behavior of ceria-based anodes in solid oxide fuel cells

Journal Article · Thu May 01 04:00:00 EDT 1997 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1837671· OSTI ID:511954

Watanabe, Masahiro; Uchida, Hiroyuki; Yoshida, Manabu ^[1]

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1. Yamanashi Univ., Kofu (Japan)

The polarization behaviors of porous samaria-doped ceria anodes coupled with zirconia electrolytes with various ionic conductivities ({sigma}{sub ion}) were investigated. The exchange current density, j{sub 0}, on such mixed-conducting SDC anodes was not influenced by the {sigma}{sub ion} at 900 and 1,000 C, whereas j{sub 0} increased proportionally to {sigma}{sub ion} at a lower temperature of 800 C. However, the dispersion of nanometer-sized ruthenium catalysts on SDC particles resulted in an increase of j{sub 0} with increase in {sigma}{sub ion} in the entire temperature range between 800 and 1,000 C. The observations are well explained kinetically, i.e., the anode performance is controlled by the rate of O{sup 2{minus}} supply to the anode layer via the electrolyte, as the anodic reaction rate becomes sufficiently high due to highly dispersed Ru electrocatalysts. Consequently, it is clear that the use of high-performance electrodes in combination with the solid electrolyte having high {sigma}{sub ion} is a prerequisite to achieving high performance of solid oxide fuel cells.

• Sponsoring Organization: USDOE
• OSTI ID: 511954
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 5 Vol. 144; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ANODES
CERIUM OXIDES
CURRENT DENSITY
IONIC CONDUCTIVITY
SOLID ELECTROLYTE FUEL CELLS
SOLID ELECTROLYTES
ZIRCONIUM OXIDES